(define isA?
  (native_function "
    Proc.new do |arguments, interpreter|
      if arguments.count != 2
        raise 'The isA? comparitor accepts two arguments'
      else
        arg1 = interpreter.evaluate(arguments[0])
        arg2 = interpreter.evaluate(arguments[1])
        if arg1.is_a?(arg2.class)
          true
        else
          false
        end
      end
    end
  "))
